Bug 15631: Koha::Cities - remove getidcity and GetCities

Bug 15631: Koha::Cities - remove getidcity and GetCities

C4::Members::getidcity and C4::Members::GetCities simply retrieved
cities info from the cities table.
The job done in members/memberentry.pl looked really weird and complicated.
Either I have missed something, or this patch can simplify it.

The expected behavior is:
1. Create a new patron => No city selected
2. Edit an existing patron => The borrowers.city value is selected
3. Add a guarantee => The borrowers.city of the guarantor is selected
4. Edit a guarantee => The borrowers.city of the guarantee is selected

Test plan:
Confirm that the expected behaviors are the ones before and after this patch.

Signed-off-by: Natasha <tasham_8@hotmail.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Brendan Gallagher brendan@bywatersolutions.com